1. Field of Invention
The present invention relates to a projector which includes a light source device having a lamp information carrier circuit board equipped with a lamp information carrier element for determining use and nonuse of a light source, and a lamp information detection circuit board for detecting information from the lamp information carrier circuit board.
2. Description of Related Art
Hitherto, a projector has been known which includes an electro-optical device for forming an optical image from a light beam emitted from a light source according to image information, and a projection lens for enlarging and projecting the image formed by the electro-optical device. Such a projector has been widely used for multimedia presentations at conferences, academic meetings, exhibitions, and the like.
In such a projector, in order to ensure stable brightness and color development state of the projected image, a light source device has been conventionally utilized in which a light source lamp, such as a metal halide lamp or a xenon lamp, is fixed to a reflector and is housed in a lamp housing. The lamp housing is provided with, at the outer periphery thereof, a lamp information carrier circuit board equipped with a fuse serving as a lamp information carrier element for determining use and nonuse of a light source.
On the other hand, the projector body includes a lamp information detection circuit board for detecting information from the lamp information carrier circuit board, and is configured so as to total up the lamp lighting time of the light source device, and to forcibly shut down the light source lamp when the light source lamp reaches its application limit, or to display on a projection screen to that effect. More specifically, when a new light source device is mounted in the projector body, (1) the lamp information detection circuit board and the lamp information carrier circuit board are connected, (2) the lamp information detection circuit board confirms the presence of an electrical continuity of a fuse provided on the lamp information carrier circuit board, (3) a total lamp operating time recorded in the device body is reset, and (4) the fuse of the lamp information carrier circuit board is cut off and totaling up of operating time of the light source device is started.
Such a lamp information carrier circuit board and a lamp information detection circuit board are stacked inside the device so that the lamp information detection circuit board covers the fuse.
While projectors are sometimes kept installed in a conference room or the like for a presentation, they are sometimes brought in as necessary, or are stored in elsewhere after use. Accordingly, it is necessary to improve portability in order to facilitate transportation, and a further reduction in size is demanded.
However, if the lamp information carrier circuit board and the lamp information detection circuit board are disposed so that the lamp information detection circuit board covers the fuse, a space is required inside the device having the height greater than the total thickness represented by the sum of the thickness of the lamp information carrier circuit board, the projecting size of the fuse provided on the lamp information carrier circuit board, and the thickness of the lamp information detection circuit board. Therefore, it is difficult to achieve a reduction in size of the projector.
One object of the present invention is to provide a projector which at least is able to facilitate a reduction in size.
A projector of one exemplary embodiment the present invention includes a light source device having a lamp information carrier circuit board equipped with a lamp information carrier element for determining use and nonuse of a light source, and a lamp information detection circuit board for detecting information from the lamp information carrier circuit board. The lamp information carrier circuit board and the lamp information detection circuit board are preferably stacked so that the lamp information detection circuit board does not overlap the lamp information carrier element of the lamp information carrier circuit board.
According to this exemplary embodiment the present invention, since the lamp information carrier element is not provided between the lamp information carrier circuit board and the lamp information detection circuit board, it is possible to dispose the lamp information carrier circuit board and the lamp information detection circuit board close to each other. This may reduce the total thickness of the boards as compared to a conventional device, even if they are stacked. Therefore, it is possible to achieve a reduction in size of the projector.
In the foregoing, the lamp information carrier circuit board and the lamp information detection circuit board may preferably be electrically connected via an urging device.
Since the urging device is formed so as to be brought into contact with the lamp information detection circuit by an urging force, this makes it possible to automatically establish electrical continuity by only accommodating the light source device in the projector.
In addition, the urging device may preferably include a fixed part, fixed to one of the lamp information carrier circuit board and the lamp information detection circuit board, and a contacting part having a contacting surface urged toward one of the lamp information carrier circuit board and the lamp information detection circuit board which is not provided with the fixed part and contacting one of the lamp information carrier circuit board and the lamp information detection circuit board which is not provided with the fixed part. The contacting part may preferably be composed of a plate spring.
If the contacting part is composed of a plate spring in this way, it is possible to simplify the structure, as compared to a case in which the contacting part is composed of a coiled spring or the like, whereby manufacture of the urging device is facilitated. In addition, when accommodating the light source device in the projector, the contacting surface of the contacting part may be moved by an urging force along the surface of the lamp information detection circuit board or the lamp information carrier circuit board while contacting. Therefore, it is possible to remove dust and the like adhered to the contacted surface of the lamp information detection circuit board or the lamp information carrier circuit board. This makes it possible to prevent contact failure between the urging device and the lamp information detection circuit board or the lamp information carrier circuit board beforehand.
In addition, the urging device may preferably be provided on the lamp information carrier circuit board.
This may allow the urging device to be replaced each time the light source device is replaced as compared to a case in which the urging device is provided on the side of the projector. Therefore, even if the projector is used for many years, the urging force of the urging device is not decreased, and it is possible to easily maintain electrical connection between the boards.
Furthermore, the contacting part may preferably be gold-plated.
This may prevent the contacting part from being oxidized to rust, and it is possible to positively secure electrical continuity even if it is used for a long period of time.